Bulk butter package



m 3, was B. w. BRANDT ETAL 3,379,537

BULK BUTTER PACKAGE Filed Sept. 14, 1964 J 29 J INVENTORS Z6 27 Ban; W BRA/V07 F /G. 5 Wu r0? H PAS/140835 ATTORNEY United States Patent Ofiice 3,379,537 Patented Apr. 23, 1968 3,379,537 BULK BUTTER PACKAGE Boyd W. Brandt, Minneapolis, and Walter H. Rasmussen, St. Paul, Minn., assignors to Waldorf Paper Products Company, St. Paul, Minn., a corporation of Minnesota Filed Sept. 14, 1964, Ser. No. 396,261 2 Claims. (Cl. 99-179) ABSTRACT (9F THE DISCLOSURE A corrugated tubular container having upper and lower closure flaps for use with a product such as bulk butter, the inner liner of the container having a moistureproof film such as polyolefin thereon, at least the upper surfaces of the lower closure flaps having pinholes through the film and liner, the other liner being substantially imperforate.

This invention relates to an improvement in butter container and deals particularly with a corrugated paperboard container used in the shipment of bulk butter and the like.

Bulk butter is oftentimes shipped from relatively small creameries where the butter is churned to larger establishments where the butter is packaged. This has oftentimes been done by inserting the butter into a bag of plastic or other material enclosed within a corrugated paperboard shipping container. In some instances, the butter is merely placed in the outer shipping containers lined with two strips of parchment paper, wax paper, or the like. During recent years, the butter has also been contained and shipped in a corrugated paperboard container having an inner liner of polyethylene or a similar polyolefin film. While shipment in such cases has been generally successful, there is a tendency for such container to retain the Water which results from inserting the Wet liner sheets in the case. It is an object of the present in.- vention to provide a butter container which avoids the previous difliculties.

An object of the present invention resides in the provision of a butter container comprising a blank of corrugated paperboard lined with a coating of polyethylene or a similar polyolefin. The bottom flaps of this container, which form the lower closure upon which the product rests, are punctured with a considerable number of apertures through the film which are perhaps the size which would be formed by a common pin. After the bottom of the container is closed, it is treated in the usual manner.

Usually, two sheets of parchment paper are placed in the container in intersecting relation, the width of the paper usually being slightly wider than the width of the container walls so that the entire interior of the container is lined. Before these strips are inserted, they are soaked in water to make them pliable and to permit them to adapt themselves to the shape of the outer container. As a result, these sheets are normally thoroughly soaked when they are inserted in the container. A large glob of butter is then dropped into the container, and the container is filled with a predetermined Weight of butter. This operation is usually done manually. The butter also adds to the moisture within the container. The ends of the liner strips are folded over the butter and the top of the container is closed. The butter is then stored and shipped in a refrigerated state to the packaging plant. Here the butter boxes are cut or torn open, and the butter is fed into an extruding machine which forms the butter into blocks of the proper size. The individual blocks are then usually wrapped and inserted into an outer carton.

With containers formed in the conventional manner and lined with a lining of polyethylene, the moisture within the container oftentimes is retained within the container due to the fact that the bottom closure flaps meet in abutting relation at the center of the container, and this portion of the container is covered by the two thicknesses of liner sheet held in place by the weight of the butter. If the moisture drains from the container, the drainage is concentrated at the edges of the flaps, this concentration of moisture materially weakening these local areas of the container. However, there is usually a considerable area of the bottom flaps which is exposed to the free liquid in the bottom of the container due to the fact that the lining sheet is not fitted closely to the inner surface of the container and due to the fact that the butter is of irregular shape and the liner sheets are oftentimes wrinkled.

We have found that if the bottom flaps only of the container are perforated with a considerable number of pinholes, the free moisture may drain through these pinholes at a very slow rate, avoiding oversaturation of any local area of the container bottom. In other words, the pinholes enable the free water to be absorbed in a greater area of the paperboard, thus avoiding the oversaturation of local areas which normally will be found along the edges of the bottom closing flaps. As a result, the strength of the paperboard is usually not affected to the extent that the strength of the paperboard will be reduced to the breaking point. At the same time, the free water within the container is slowly drained away so that when the containers are opened, there will be no free Water present.

A feature of the present invention resides in the provision of a container of the type described and comprising a blank of corrugated paperboard having an inner liner of polyolefin film and in which pinholes or small perforations are provided in the coated liner to permit moisture to drain slowly into the interior of the corrugated paperboard.

These and other objects and novel features of the present invention will be more clearly and fully set forth in the following specification and claims.

In the drawings forming a part of the specification:

FIGURE 1 is a perspective View of the butter container in closed condition.

FIGURE 2 is a perspective view of the container in open position with the liner sheets in place.

FIGURE 3 is an enlarged sectional view through a portion of the paperboard forming one of the bottom flaps.

FIGURE 4 is a sectional view through a portion of the filled container, the position of the section being indicated by the line 4--4 of FIGURE 1.

FIGURE 5 is a diagrammatic view of the blank from which the container is formed.

The container A illustrated in the drawings is of generally conventional form. As indicated in FIGURE 5, the container is formed from a blank cut and creased to provide for tubularly connected walls. Four wall panels 10, 11, 12, and 13, are hingedly connected along parallel fold lines 14, 15, and 16. A glue flap or stitch flape 17 is hingedly connected to one end panel of the series, such as the panel 13, along a fold line 19 which is parallel to the previouslydescribed fold lines, the glue flap being connected to panel 10 to provide the tubular form. The upper edges of the panels 10, 11, 12, and 13 are connected along a line of fold 20 to top closure flaps 21, 22, 23, and 24. The lower edges of the wall panels 10, 11, 12, and 13 are also connected along the fold line 25 to bottom closure flaps 26, 27, 29, and 30, respectively. The various closing flaps are proportioned so as to meet in edge-abutting relation when the container is closed.

The paperboard from which the container is formed is illustrated in greatly enlarged form in FIGURE 3 of the drawings. The paperboard includes an imperforate outer liner 31, a corrugated medium 32, and an inner liner 33. The inner liner 33 is coated with a film or coating of polyethylene or other suitable plastic material, indicated at 34. Usually the coating 34 is extruded onto the liner 33 prior to the combining of this liner with the corrugated medium 32.

As is also indicated in FIGURE 3, the inner liner 33 and its coating 34 are perforated at intervals as indicated at 35. These perforations or apertures 35 are approximately of the size which would be formed by inserting common pins through the liner. Actually, the perforations usually close up due to the nature of the paperboard after the perforating operation. However, the coating 34 remains perforated, allowing free moisture to be drawn into the paper by capillary action. Normally only the bottom flaps are perforated, although the perforations may also extend into the lower portions of the side walls if desired. Usually the perforation of the flaps only is preferable, as the bottom closure is formed of two layers of paperboard so that the slight impairment of the strength of the uppermost layer of paperboard is relatively immaterial.

In the use of the containers A, each container is set up in a rectangular form and the bottom closure secured closed by any suitable means such as by stitching, gluing or taping. The two liner sheets 40 which are preferably of grease resistant paper are then removed from the tank or tray in which they have been soaked and inserted in the container with the center portion of each liner sheet overlying the bottom closure, and the ends of the liner sheet are folded outwardly over the top closing flaps. When the liner sheets have been inserted, the structure appears as indicated in FIGURE 2 of the drawings. Usually the liner sheets 40 are of slightly greater width than the width of the walls so that the corners of the two sheets or the edges thereof are slightly overlapped. This is facilitated by the fact that the paper is very limp in its soaked condition. As the liner sheets are inserted in the container directly upon removal from the soaking tank, this normally results in a substantial amount of free water in the bottom of the container as the water drains to the bottom of the container from the side walls. A big mass of butteris picked up and dropped into the container and then the mass is adjusted until the proper weight of butter is contained. At this point, the top of the container is closed in any suitable manner and the container is ready for shipment.

The free water at the bottom of the container gradually drains through the pinholes in the inner coating and into the interior of the corrugated board moistening this board to some extent. However, as the moisture is insuflicient in any one area to greatly impair the strength of the paperboard, the container remains in good condition during shipment and storage. When the butter arrives at its destination, and the container is opened, all the free water in the container has been dissipated but without injury to the container.

As a specific example of a structure which has been found practical, perforating wheels have been formed which penetrate the coating and inside liner. These wheels are provided with radially projecting pins perhaps threeeighths of an inch long. These pins are similar to steel phonograph needles having shanks about 0.065 inch in diameter and having the outer three-sixteenths of an inch sharply tapered to a point. The wheels are supported so that only the points of the pins penetrate the inner coating and liner. The pins are spaced to provide perforations at one inch intervals both laterally and longitudinally of the flaps.

One of the unusual features of the invention lies in the use of the perforated flap structure in combination with butter which contains salt. After use, an examination of the flaps shows small areas of salt at each pinhole through which moisture has drained. It appears that as the moisture slowly drains into the corrugated medium, salt is deposited in the pinholes, acting to at least partially seal these holes. As a result, the salt serves to reseal the container flaps after the pinholes have served their purpose.

In accordance with the patent statutes, we have described the prinoiples of construction and operation of our butter container; and while we have endeavored to set forth the best embodiment thereof, we desire to have it understood that obvious changes may be made within the scope of the following claims without departing from the spirit of our invention.

We claim:

1. A bulk butter package comprising a corrugated paper-poard container made from a sheet of corrugated paperboard including a pair of spaced liners with a corrugated medium sandwiched therebetween and secured thereto, said corrugated sheet being cut and creased to provide four walls connected in rectangular relation, integral bottom closure flaps hinged to the lower edges of said walls and integral upper closure flaps hinged to the upper edges of said walls, the surface of the inner liner having a film of polyolefin material thereon and the upper surfaces of the bottom closure flaps in sealed relation having a plurality of pinholes therein, said pinholes extending through only the polyolefin film and the inner liner of the corrugated sheet, the outer liner of said corrugated sheet being imperforate, a pair of intersecting strips of water soaked paper in said container, each of said intersecting water soaked paper strips overlying two opposed walls and the inner surface of said bottom closure flaps, bulk butter enclosed within the container, the ends of said paper strips overlying the top of the butter, and said bottom and top closure flaps being in sealed condition whereby the pinholes in said bottom closure flaps permit the water in the package to drain slowly into the interior of the corrugated paperboard;

2. The structure of claim 1 and in which the butter contains salt, and in which the pinholes-are at least partially sealed with salt deposited therein.

References Cited UNITED STATES PATENTS HY MAN LORD, Primary Examiner. 

